For a little while now (sorry, hashtag lazy) miniloader inserters have been showing some UI elements when Bob's loader mod is installed. I'm not sure what, exactly, is making them visible, and it could be an interaction with a third mod. I have not taken the time to fully debug it down to the minimum possible, simply because it is so reproducible for me.
I believe that is unintended, and there is some code to try and, well, not do that. Seems maybe not working with latest v17 Factorio, bob's inserters, and your mod. All updated as of this very second via the mod portal.
If you can't repo please let me know and I'll dig down into what, exactly, is happening to break things. I'd just rather be lazy and avoid the half hour or hour digging around more item prototypes and entities in-game to figure it out, or bisecting down mods to find the exact combination. Factory needs to grow.